Alternative cosmology can include any physical science-based cosmological model of the Universe proposed as an alternative to the standard Big Bang model. Apart from the Steady State theory, most of them deny that space or the universe is expanding.

It should be remembered that "alternative medicine" which actually works is called "medicine". The same care needs to be taken with "alternative cosmology".

Steady State theory is a cosmological model developed as an alternative to the Big Bang theory. The original Steady State theory is now considered obsolete but was revised into Quasi-Steady State Cosmology by some of the same authors who proposed the original Steady State model.

Space-time diagram in the steady state theory. Though stars (white) expand exponentially and quickly disappear over the event horizon (green), the theory assumes that new matter would be continuously created. The observer would see infinite red-shifted ancient stars on the light cone (yellow). This view failed to explain almost homogeneous microwave background radiation.

Steady-state cosmologies involving more than an Earth-centered Universe, date back to the Renaissance when the Earth was no longer the theoretical center of the cosmos. Most steady-state cosmologies until the 20th century proposed an infinite universe in time and space, of a generally uniform density and sustained appearance, without the creation of new matter. In the 19th century collectively these theories were the dominant models in cosmology before Hubble's discovery in the 1920s of redshifts and its implication of an expanding universe and galaxies beyond the Milky Way. There was no reason then for most theorists to think that the universe was not in a generally unchanging condition, with only minor relative motions and evolutionary cycles. Following Hubble's redshift discoveries in the 1920s, British physicist Sir James Jeans suggested a steady state cosmology based on a hypothesized continuous creation of matter in the universe to accommodate an expanding universe. The idea was later revised in 1948 by the astronomersFred Hoyle (1915-2001), Thomas Gold (1920-2004) and Hermann Bondi (1919-2005). This Steady State theory (SST) version asserts that although the universe is expanding, it nevertheless does not change its appearance over time (the perfect cosmological principle) because of new matter creation; the universe has no beginning and no end.

According to Hermann Bondi, the SST has two advantages over the Big Bang theory. First, it eliminates any problems concerning the age of the universe, and second, it avoids the question of where the universe came from in the first place, as according to the SST the universe is infinite in age and extension.

The main idea behind the steady state theories is the perfect cosmological principle, which states that from a largescale point of view the universe should look the same regardless of the observer's position in space and time. The principle also suggests that the laws of physics operate in the same way in all space at all points in time throughout the universe. This idea of the laws of physics being immutable is in contrast to the Big Bang theory which proposes the laws of physics operated very differently at the first moments after the theorized birth of the universe. During the period 1944-1966 many physicists and astronomers supported steady-state models in general, and the SST version (Hoyle, Gold, Bondi) in particular.

The SST proposes an eternal universe but does not imply a static universe. According to steady state theorists the universe exists in a steady state condition with an expanding universe and galaxies of all ages continuously moving through life cycles, as well as some recycling renewals. The SST claims that matter is continuously being created, either evenly throughout space, or selectively surrounding galactic black holes. This is the most controversial aspect of the theory.

There are problems which can be ascribed to the idea that matter is undergoing a continuous creation throughout the universe. As pointed out by critics of the theory most versions of such proposals would seem to violate the principle of the conservation of matter. Proponents of the SST dismissed such criticisms by claiming that the continual creation of matter might involve a background energy or particulate field such as the Zero Point Field as being the source of this creation material, and that it had not been contradicted by any observational evidence. Bondi proposed that newly created matter would likely be in the form of hydrogenatoms, whether wholly or singly created as electrons and protons. The rate of creation required by the perfect cosmological principle would be satisfied even if allegedly every 109 years one hydrogen atom were generated per every liter of space. According to the SST such a small rate of creation would not be observable at stellar scales, only at the largest universe scales concerning a constant density of matter.

Another problem was that SST theorists could offer no direct evidence for this creation process. Different possible mechanisms were offered by Bondi and others but critics considered such proposals as ad hoc for the purpose of maintaining the desired constant (steady-state) density. Contrary to the Big Bang requirement concerning greater galactic densities in the past (based upon an expanding universe), steady-state theorists believed that only a constant matter-density of the universe could explain the even galactic densities that they believed were being observed at the farthest distances of the universe as well as close-by.

In the early 1930s, before his endorsement of the Big Bang model, Einstein developed his own Steady-State model involving the new creation of matter to maintain a constant matter density of an expanding universe. The new-creation mechanism(s) discussed were similar to prior proposals by Paul Dirac and James Jeans. He wrote a related paper of this proposal but decided to set it aside in his archives rather than publishing it.

A present day mainstream proposal of the 'Continuous creation of matter' involves Hawking radiation and the idea that near the event horizon of black holes, particles can be created by vacuum fluctuations that could create new matter in this universe. This could be in the form of electrons, positrons, and possibly protons and anti-protons. This idea seems to have kinship with the steady-state creation of matter and 'C' field matter creation of Quasi-steady-state cosmology explained below, but on a much smaller scale.
By new-matter creation and energy radiation, black holes accordingly could evaporate out of existence.

The Steady State theory did not decline because of the weaknesses associated with the theory of continuous creation of matter, but due to its believed failure to produce accurate predictions according to interpretations of new observations. The Steady State theory predicted that the Universe should look the same from all positions in space and all points in time. The first evidence that shook this prediction came in 1950s and 1960s with data from several radio telescopes suggesting that in the distant past the universe and galaxies looked different than they do today concerning more radio-frequency radiation. Another group of observations related to the discovery of quasars (quasi-stellar objects) that seemed to exist only at great distances but none were observed in the local part of the Universe. These observations were still open to different interpretations and might have been explained by SST, but it was the discovery of the cosmic background radiation in 1965 by Arno Penzias and Robert Wilson that turned the tide.

The microwave background was a prediction by some Big Bang theorists, as being a possibly observable remnant of the original Big Bang beginning. After the discovery of background radiation, SS theorists were unimpressed by the discovery, explaining the microwave background radiation away as simply being the heat from starlight in our galaxy and the temperature of matter in intergalactic space absorbed by the fine grains of matter, from galaxies, as predicted by astronomers and theorists alike for many prior decades. However the observed great uniformity of this background radiation temperature was much more difficult to explain by SST. To explain this temperature uniformity SS theorists came up with the hypothesis that iron and/or carbon "needles" could have evenly distributed the microwave background temperature given enough time, but such proposals were not well received because of their ad hoc nature. After the discovery of the microwave background radiation and of its great uniformity, most SS theorists of the time eventually abandoned the SST in favor of the Big Bang model.

Other issues with this theory are that if it was true we'd see everywhere galaxies in all their evolutionary stages from pristine gas clouds to others in quasar mode and/or bursting with countless young stars, to finally arrive to mature systems as ours – compare this with what happens in the real Universe where just young, small, and actively star-forming galaxies are seen at high redshifts. They'd have just hydrogen and not heavier elements as just the former is being made ex-nihilo, but all systems observed to date have hydrogen and some helium in agreement with what is predicted by the Big Bang theory. Also, even with an expanding Universe carrying away the old galaxies, some legacy of them should be detectable beyond a cosmic microwave background very different of the real one (see also below), including with some luck systems much older than ours, and finally remains to be seen how the large-scale structure of the Universe with galaxies in web-like filaments surrounding large voids, that simulations that employ the current mainstream cosmological model reproduce well, could be created in this scenario.

In a series of scientific publications in the late 20th century, Fred Hoyle, Jayant V. Narlikar and Geoffrey Burbidge proposed an updated version of the Steady State theory; the new model contains many differences from the original model. The new model known as the Quasi-Steady State Cosmology (QSSC) was alleged to be compatible with the same evidence that supports the Big Bang and claims to explain other evidence better which does not fit well with the Big Bang model. The QSSC is compatible with the existence of the cosmic background radiation. The QSSC proposed that this radiation could be accounted for by so-called "integrated starlight" which was a background radiation caused in part by Olbers' paradox involving the highly redshifted distant and infinite universe. In order to account for the uniformity of the background radiation, the QSSC posited a fog effect associated with microscopic iron particles that would scatter radio waves in such a manner as to produce an isotropic CMB. This proposed mechanism had some similarities to a prior steady-state proposal then dubbed "cosmic iron whiskers," which also accordingly served as a thermalization mechanism.

There was/is no direct astronomical evidence as to the extent of such iron particles (later carbon was additionally proposed) in galactic or intergalactic space, but Hoyle, Burbidge, and Narlikar emphasized that such particles had been well-studied in the laboratory and that their optical and temperature distribution properties could explain thermalization of background radiation. They also emphasized that this mechanism may not be needed at all in the thermalization process since the most distant galaxies were redshifted to a very great extent in an infinite universe, something like Olber's paradox excepting that only the microwave background would be produced. This radiation would pass through an overall 'fog' of galactic and intergalactic hydrogen of both atomic and molecular forms, producing uniform re-radiation in an infinite universe. By this time the Quasi-steady state model had only a small following. Negative comments concerning this new CMB thermalization proposal generally characterized it as ad hoc speculation, and the Hoyle-Narlikar's derivated result of a featureless CMB has been refuted by the COBE mission, and especially WMAP and Planck later, that show many small anisotropies on it.

According to the new theory instead of one Big Bang, a cyclical series of smaller mini-bangs accordingly occurred throughout the history of the Universe at infrequent intervals. The mini bang events would have been caused by a phenomenon described as the creation field (C-field). According to the QSSC the C-field exists only in certain areas of the universe which are characterized by a high density of matter. Hoyle, Burbidge, and Narlikar described matter creation as taking place in these violent events of "little big bangs" involving masses as large as 1016-1017 times the mass of the Sun. In their later works they proposed the decreased magnitude but increased frequency of these creation events, and that most events were probably longer lasting but less violent than originally proposed, but still involved C-fields and in either case these events are posited to explain the observed large-scale structure of the Universe, with said "mini-bangs" having taken place in the (almost) galaxy-empty voids.

Most cosmologists have ignored the QSSC model associating it with the original SST proposal, and likewise consider it disproved for the same reasons. Narlikar and a small group of researchers are the only modern day supporters of the theory.

Plasma cosmology is a term describing a loose set of non-standard ideas about cosmology. Its central idea is that the dynamics of ionized gases (or plasmas) plays a decisive role in the physics of the Universe at scales larger than the Solar System. Plasma cosmology has never had the support of most astronomers or physicists. Plasma cosmology theory was being worked on in the 1960s by Hannes Alfvén, Oskar Klein and Carl-Gunne Fälthammar, concerning their related published works in scientific journals. Plasma cosmology argues for an eternal universe and relies on plasma physics to explain many anomalous cosmological observations by appealing to electromagnetic forces.

There is no consensus in theoretical physics to this model, or a consensus view amongst its adherents concerning the exact mechanics of the model.

There have been a number of cosmological proposals involving electric and electromagnetic influences of the Universe at the largest scales, promoting some ideas similar to Plasma Cosmology. They have been collectively called Electric Universe (EU) models. However, the few active Plasma Cosmologists today generally distance themselves from EU association since at least some of such proposals involve pseudoscience.

In 1991, Eric J. Lerner, an independent researcher in plasma physics and nuclear fusion, wrote a popular-level book explaining possible problems with the Big Bang model, while supporting and promoting Alfvén's plasma cosmology, titled The Big Bang Never Happened. Although Lerner, by way of his book and other promotions, has done much to make the public and theorists aware of Plasma Cosmology in general, the theory continues to be generally ignored or rejected by most cosmologists because of its characterized speculative nature and lack of evidence to support it.

A general replacement for the original Alfvén-Klein plasma cosmology was proposed called "Quantum Magnetohydrodynamics (QMHD)", a "Theory of Everything" (TOE), which continues in development at the Royal Institute of Technology in Stockholm; no consensus version of Plasma Cosmology exists amongst its few active practitioners and theorists.

Astronomers and theorists Halton Arp, Geoffrey and Margarite Burbidge, William Tifft, and others beginning in the 1960s and 1970s, saw what they believed to be problems with quasars and their calculated distances and brightnesses based upon their observed redshifts. Based upon observations they proposed that some quasars were much closer than their redshifts would seem to indicate based upon Hubble formula calculated distances. Some quasars appear(ed) to be in front of galaxies with smaller redshifts. Other groups of quasars appeared to be ejected from the center of some galaxies trailing away in a linear fashion. Critics asserted these were just coincidental alignments.

These theorists proposed that the observed redshifts of at least some quasars were not distance indicators but instead would have another explanation such as being intrinsically redshifted, gravitationally redshifted, or variable mass ideas and related cosmologies. Also because of the observations of the vast web and bubble-like structures, great walls of galaxies, organized clusters and superclusters, as well as very old appearing galaxies at the furthest distances, these theorists proposed or favored much older or infinite-aged Universe models.

All of the models above are generally known historically by theorists and astronomers. But most of the alternative cosmological models below are totally unknown to both theorists and laymen alike. Of the few models below which have been commented on by the scientific community, most of these have been described negatively as unlikely hypotheses at best (rather than theory), criticized in one way or another, or described as fringe physics or pseudoscience. Few such criticisms have involved detailed explanations. Some models below propose pushing gravity concepts or aether theories. Some of these models and theories are self-published or appear in fringe journals such as Apeiron, Physics Essays and the Journal of Cosmology. Most alternative theorists come to realize that very few scientific journals will consider publishing alternative theory proposals, and if so the cost of publishing in the few peer-reviewed journals that might accept them, could be high. Most of such papers are summarily dismissed by the most well known journals, maybe without even being read, once it is realized that the underlying theory is not mainstream. There have been few exceptions. It also helps, concerning publication of alternative theory, if some association exists between the author(s) and an academic institution of some kind, whose name and related identification are at the heading of the paper. Titles and credentials of the authors might also be considered by publishers, such as Dr., Ph.D., Professor, etc., in the related field. These personal titles and that of an institution might help in some cases to get published, but the articles themselves must warrant the merit of publication, from the publisher's perspective.

Most alternative cosmologies above and below claim that the Big Bang model is contradicted in many ways, including observationally and theoretically. Claims of observational contradictions include the observed uniform or decreasing galactic densities at increasing distances (where an expanding universe should have been denser in the past), old-appearing galaxies in the most distant parts of the observable Universe, etc., as well as theoretically, such as alleged violations of the principles of thermodynamics explained here, the flatness and horizon problems requiring the Inflation hypothesis, the dark matter and dark energy hypotheses, magnetic monopoles, etc. Such asserted Big Bang problems/contradictions, changing theory, and ad hoc hypotheses were the reasons often given for the proposal of most of these alternative theories/hypotheses in the first place.

The following list includes some of the more accessible or promoted alternative cosmologies out there but is still just a sampling concerning alternative cosmologies in general. Many of these cosmologies are still being proposed and updated by active theorists on the net and elsewhere.

The pioneer of radio astronomy Grote Reber (1911-2002) proposed a model of a stable non-expanding universe in which redshift was due to repeated absorption and re-emission or interaction of light and other electromagnetic radiation by low density dark matter, over intergalactic distances, similar to previous tired-light proposals before him. He published an article called "Endless, Boundless, Stable Universe" which outlined his theory. He also published a less technical article called "The Big Bang Is Bunk". Today "tired light" proposals to explain redshift-distance relationships have been consigned to consideration only in the fringes of astrophysics. The primary reason is that these proposals in general cannot explain time dilation as observed concerning Type 1a supernovas and other distant events.

The Finnish astronomer Toivo Jaakkola (1941-1995) invented his own steady state model known as Equilibrium Cosmology. Jaakkola's model, in the framework of an infinite Universe, led him to adopt the so-called perfect cosmological principle, that of Hoyle, Gold, Bondi, however his model did not require the continuous creation of matter since accordingly the universe was not expanding. To explain redshift in his model, [1] Jaakkola proposed that redshifts be interpreted as a quantized loss of energy from the photon to a vacuum composed of gravitational quanta. In his model he also invoked a pushing gravity mechanism which underlies the Universe in which all energy conversion processes exist in a state of continual equilibrium.

John Kierein is a scientist who has argued since the 1960s that the universe is not expanding. Kierein uses the Compton Effect interpretation to explain quasars and the redshift. According to his theory solar redshift is due to Compton scattering of solar radiation through the electrons in the solar atmosphere. He published his theory in a paper in 1968 which can be found here. If the Compton effect interpretation is correct then there should be expected a blurring image in the galaxy, however this is not usually observed. Kierein has responded to the criticism of his theory on his website. He has published a paper in 1990 claiming the Compton effect supports a static model of the universe. He also supports a pushing gravity theory. The astrophysicist Edward L. Wright (a staunch, well known Big Bang proponent) has criticised the theories of Kierein, and on his website Kierein's Erroneous Compton Model for the Redshift claiming Kierein is invoking an unknown speculative physical effect and not the Compton Effect as Kierein claims.

David Calder Hardy has proposed the Genesis Continuous Theory which claims the universe is infinite, boundless and recycles itself. His theory is based on the activity of stars which he claims recycles all the matter and energy in the universe. According to his theory newborn stars are much larger than mainstream astronomy assumes and the sun is 100 billion or more years old. He writes that the Sun processed a full complement of elements; as well as having given birth to 20 or more planets at 2 to 2.5 billion year intervals, and that the oldest ones are heading away into space collecting their nebulae of gas to eventually become the next generation of stars. He wrote a book Genesis Continuous in 1973, a revised edition in 1995 and an updated edition online in 2005. His theory has not been reviewed or considered by the scientific community.

Many alternative cosmology models endorse aether concepts, however the following are most notable for placing a central role on aether in the universe. Leonid Sokolow wrote a book A Dual Ether Universe: Introducing a New Unified Field Theory (1977) endorsing pushing gravity, an aether to replace Relativity and a non-expanding Universe. Sid Deutsch (1919-2011) author of Einstein's Greatest Mistake: Abandonment of the Aether (2006) also rejected the Big Bang theory. According to Deutsch the universe is filled with an aether fluid and recycles itself infinitely.

The Aethro-Kinematics theory of Steven Rado (1920-2012) is based on an all-pervading aether in the universe. The theory claims to refute the Big Bang and Relativity by resurrecting René Descartes's theory that the Earth and all the planets are carried around the Sun by an "Aether vortex." He published a book Aethro-Kinematics describing his theory in 1994 and another book Aethro-dynamics in 2009. In the Aether Theory of Reginald Norgan the aether substance is constructed of identical aether atoms called Aethons. Aether concepts are considered fringe physics and none of these authors published their theories in scientific publications.

In the 1980s Arnold Gulko presented the Universe Cycle Model which claims that each galaxy undergoes separately a cyclic process of birth, growth, aging, death, and rebirth within an infinite universe. According to his model quasars are stages of galactic evolution prior to formation of a normal galaxy. He last revised his theory in 2008 which can be found here. Gulko has self-published many books and papers describing his ideas but his model has not appeared in any scientific publications.

In 1993 Henry P. Dart III in a paper for the fringe physics journal Apeiron proposed the Exponential Decay Hypothesis which advocated a hierarchical universe, infinite in space and in time, with no beginning and no end. According to the hypothesis, energy lost by photons is converted into neutrinos having very small masses which eventually are attracted to galactic centers where they are "recycled" into electrons and protons.

An engineer J. L. Riley in 1993 published a theory of a Steady State Universe in a book titled What Matters, No Expanding Universe, No Big Bang. His theory claims the galactic redshift is just the effect of light turning into matter as it ages, and not evidence for an expanding universe. Riley also suggests that photons are a self-propagating electromagnetic torrent field. He proposes that time is multidimensional and claims a kinship of his model with String Theory conceptually concerning cosmology.

Rufus Young in 1996 proposed the Steady State Galaxy Theory which claims at the center of each galaxy is a "neutroid" which acts to constantly recycle all the matter and energy in the galaxy. According to his theory the galaxies form huge recycling systems which will carry on indefinitely. His theory proposes that neutroids (what we presently call galactic black holes) are similar to neutron stars but are larger and have reached a size where the pressure and temperatures at their surfaces are great enough to generate nuclear fusion processes. The theory is based on the activity of these "neutroids." Young equates his neutroids with Seyfert galaxies (active galactic nuclei, AGN's) and contends all large galaxies have gone through one or more neutroid cycles. The term neutroid is of his own creation and does not appear in any other cosmological literature. Young last revised his theory in 2005, and his theory does not appear in any scientific publications.

The Meta Model Cosmology was proposed by Tom Van Flandern in 1999. He was an American Astronomer (deceased) specializing in celestial mechanics. His book titled Dark Matter, Missing Planets and New Comets: Paradoxes Resolved, Origins Illuminated he described as presenting "A new cosmological model of the universe, arrived at deductively, in which the universe is infinite in five dimensions and filled with substance at all scales. In it, gravitation produces the redshift of galaxies, is limited in range, and is produced by the pushing action of tiny agents on matter." Van Flandern was a fairly well-known "alternative model" theorist who claimed the universe is not expanding and argued for a static universe. His article Top 30 Problems with the Big Bang is frequently cited by advocates of alternative cosmology. Van Flandern also endorsed other unorthodox ideas such as the exploding planet hypothesis for the formation of the asteroid belt and his own model of pushing gravity, supported by his own theoretical physics concerning gravity mechanics.

In 2002 Conrad Ranzan proposed a model known as the Dynamic Steady State Universe Theory (cellular universe) which claims while space does expand and in doing so gives rise to the cosmic redshift, the universe itself does not expand. The model suggests that the universe is infinite with no Big Bang moment of creation and no need for dark matter, dark energy or inflation. Although referred to as "steady state" model it has little to do with the traditional concept. It is steady only in so far as it does not require a beginning or end, and exists in some balance. The theory has been described by critics as fringe physics by introducing an ad hoc hypothesis titled "the cellular structure of the universe."

Alexandra Correa and Paulo Correa have presented a model based on aetherometry that claims the universe is infinitely old; time and space manifolds are separate. Their theory claims the microwave cosmic background radiation is explained by the continuous cosmological formation of electrons (and attendant gravitons) from the aether. Their model takes influences from Wilhelm Reich and his theory of orgone energy and the aether theory of Harold Aspden. If you can make sense of their pseudoscience, you can read it here.

Ron Pearson, an engineer, claims the Big Bang has many flaws and proposed his Big Breed Theory to replace it. He has written a number of books such as The Big Breed Theory, Dark Energy Mystery Solved and other books explaining his theory. According to his theory space is permeated by something Pearson calls the i-ther. Pearson postulates the existence of an "intelligent ether" or i-ther, said to be found throughout the Universe, whereby the human mind is not a brain function alone but interacts with the i-ther as separate from the matter portion of the mind. I-ther lives on to interact with new constructs of matter in the universe at different frequencies. Apart from this diversion many of his ideas have similarities to other aether models. His theory rejects the constant speed of light in a vacuum, Relativity, and the cosmological constant. His theory has been supported by parapsychologists and spiritualists, but the scientific community has rejected it.

Joel Emerson Webb first proposed in 1993 the Contracting Universe Hypothesis which claims to explain the Hubble law, background radiation and Olber's paradox better than the Big Bang or Steady State models. His hypothesis is based around two primary concepts and postulates. First, that the cosmological redshift can be explained if time everywhere in the Universe, and therefore the frequency of light, were slower in the past than it is now. The further back in time we would go (by examining the light from ever more distant galaxies), the greater would be the slowing down of time and therefore the frequency of light, and hence the greater the redshift. Secondly, that all of nature's constants (e.g., the speed of light, the gravitational and Planck's constant, etc., plus all other entities — time, distance, the size of matter, mass, energy, charge, force, etc.) should continue to be measured as constant by hypothetical inhabitants of the Universe throughout all epochs even though, relatively speaking, all of them would be getting smaller.

The Cosmic Electrodynamic Model of Chris Lucas takes influence from plasma cosmology especially the ideas of Hannes Alfven and Eric J. Lerner. The model claims there was a local explosion in the universe caused by colliding matter and antimatter galaxies, in a much older dynamic Universe. Galactic structures and observed cosmic phenomena are the results of large scale electromagnetic forces acting, along with gravity, to continually evolve the Universe. Lucas claims black holes and dark matter are not needed to explain the Universe. He last updated his model in 2004 and it has not appeared in any scientific publications.

The Dispersive Extinction Theory (DET) was proposed by the professor of physics Ling Jun Wang in 2005. The theory interprets the cosmic redshift as the result of dispersive absorption and scattering of the star light by the intergalactic space medium during its propagation towards the earth. In his publications Wang argues that the Big Bang has a number of problems as it demands an unobservable dark mass that is 30 times greater than the observed real mass, and that Big Bang theory violates Maxwell’s velocity distribution of the thermodynamic ensemble. According to the DET the universe is stable, non-expanding and infinite in space and time. In 2012 he lectured his theory at the University of Tennessee at Chattanooga.

The engineer Bobby McGehee presented a theory known as the New Universe Theory (NUT) which claims there is a primordial universe that extends out to infinity. According to the NUT there was a conversion of pre-universe primordial matter into the matter of the Universe, occurring at the speed of light in a direction away from its starting point (now the center of the universe), and decelerating thereafter. There is no dark energy and his theory claims that matter (energy and mass) cannot be created or destroyed, and that something had to exist beforehand, forever. Therefore it had to be primordial matter or pre-primordial matter, by definition of the terms. The theory also offers an alternative explanation for the redshift. According to McGehee, the Big Bang theory has misinterpreted the redshift which has led to an expansion illusion. He published his theory in a book titled New Universe Theory with the Laws of Physics, in 2005.

The Placid Universe Model was proposed by David Noel in 2007 and was updated until 2012. The model denies that the universe is expanding, and assumes that the large-scale structure of the universe is unchanging over time but on smaller scales the activity may be intense. According to the PU model most of the redshift observed in distant celestial objects is due to Gravitational Red Shift (GRS). The model claims that red shifts are due to gravitational drag on the light quanta as they pass through matter fields, rather than due to movement away of the sources. Noel also has another webpage found here which claims to have provided complete proof that the Big Bang never happened and the Universe is not expanding. His model has not been reviewed by the scientific community.

The Plasma Redshift Theory has been advocated by a number of independent researchers. It is most notably supported by Ari Brynjolfsson in a number of papers in fringe physics journals describing his theory (see here and here). Thomas Smid has a variant of the theory based on the activity of plasma fields. Robin Whittle also has a website describing the theory. The theory should not be confused as a "tired light" interpretation of the redshift. The plasma redshift theories deny the need for black holes, dark matter and dark energy. The only supporters of these theories seem to be Electric Universe theorists, such ideas are considered fringe physics by the scientific community.

Chemical engineer Eit Gaastra has proposed an Infinite Universe Model. His theory claims Relativity can be replaced by an aether theory, that gravity acts as a pushing force and that the expansion redshift can be explained by a "tired light" hypothesis. According to his model black holes, neutron stars and degenerate gas concepts are theoretical concepts that do not exist in the universe. His model is fringe physics and has not been reviewed by the scientific community. He last updated his theory in 2010. Also see here and here.

Adam W. L. Chan claims to have been working on his Regenerating Universe Theory for two and half decades. His theory explains the expansion of the Universe as well as many other cosmological phenomena without a beginning Big Bang. Amongst the claims that his theory dismisses are Einstein's mathematics for both Special and General Relativity as being unreal and imaginary. Forces that drive galactic motion accordingly do not come from a single origin, such as the Big Bang singularity, but they come from each galaxy separately. Electromagnetic forces in waves are generated by all galaxies and both electricity and magnetism can induce the other in alternating phases with interactions between them causing spinning motions of atoms, planets, solar systems and galaxies.

He has written that the entire Universe is in a "perpetual spinning motion" of mass and energy which also forms dynamic symmetries that cause all the phenomena in the universe. His theory is influenced by Chinesephilosophy such as the concept of Yin and yang and the book of I Ching. He last revised his theory in 2011. His theory appears in no scientific publications.

The philosopher Glenn Borchardt who claims to have "50 years of theoretical, experimental, and observational experience as a scientist" developed an Infinite Universe theory in 2007. According to his theory there is an ether; light is wave motion; the galactic redshifts are due primarily to energy absorption; gravity involves a push, not a pull, light bending near massive bodies is refraction due to a dense etherosphere; galactic ages do not correlate with distance from Earth; the universe is Euclidean and not expanding; empty space and solid matter are ideas, not reality; matter has only three dimensions to it. He has presented no evidence for his theory and his ideas have been described as more philosophical than scientific. You can read his ideas here.

Borchardt has recently merged his original theory into a new model with Stephen J. Puetz titled the Universal Cycle Theory and explained in their book Universal Cycle Theory: Neomechanics of the Hierarchically Infinite Universe (2011). The Universal Cycle Theory is based on the premise that the Universe and time are both infinite and that motions of matter involve vortices (rotations) and waves (compressions-decompressions) in the ether.

The physicist David Crawford has written a number of scientific papers advocating a tired-light cosmology. His theory of Curvature Cosmology claims the universe is infinite, static and not expanding. He published a book Curvature Cosmology: A Model for a Static, Stable Universe (2006) and in 2011 published a paper titled Observational Evidence Favors a Static Universe in the controversial Journal of Cosmology, which also was published on arXiv, an online primarily-mainsteam distributor of cosmology.

The Dynamic Universe Theory was proposed by the physicist Tuomo Suntola as a unifying theory converting spacetime in variable coordinates into dynamic space in absolute coordinates. The Dynamic Universe theory relies on an overall zero-energy balance and the conservation of the total energy in interactions in space. The theory discards the space-time marriage, the Relativity principle, the Lorentz transformation, the equivalence principle, and dark energy. According to Suntola:

[The] Dynamic Universe means major rethinking of the cosmological structure and development of the universe. Instead of a sudden Big Bang switching on time, energy, and the laws of nature, the buildup and release of energy in Dynamic Universe develops in a contraction and expansion process from emptiness in infinity in the past through singularity to emptiness in infinity in the future.

See here and here. He has published his theory in a number of fringe physics journals and published a book The Dynamic Universe: Toward a Unified Picture of Physical Reality in 2011. He has stated in Tekniikka ja Talous that his original motivation was to find a numerically effective theory for satellite navigation within the Solar System, in order to avoid computationally costly calculations with General Relativity. Nevertheless, his claim has been extended to a full theory of gravity. He has defended his theory and criticized the current interpretations of tests of general relativity in a science societies' magazine Tieteessä tapahtuu in 2014.[1][2]

The Infinite Non-Expanding Universe Theory of Geoffrey Wynne-Jones is described as a "realistic alternative to the Big Bang Theory." According to some of the claims of his theory the source of all energy is gravity, the cosmic microwave background is radiation of cold matter and the temperature of starlight at 3°K, fragmentation of a neutron mass reforms hydrogen and black holes are part of the lifecycle of a hydrogen mass. Like most other theories which deny the universe is expanding his theory invokes a tired light mechanism to explain redshift. He last revised his theory in 2012 and it has not been published in any scientific publications.

The Recycling Universe Theory was described in a self-published book by James Keith Leedy in 2012. According to the theory there were multiple big bangs and the universe is infinite. He has not published his theory in any scientific publications.

The physicist Eduardo Lopez Sandoval has written a non-peer reviewed paper titled Static Universe: Infinite, Eternal and Self-Sustainable which presents alternative explanations for redshift and the cosmic background radiation. He last revised his model in 2012 but it has not been reviewed by the scientific community.

Jim Mash a chemist has proposed the Fluid Energy Theory which is based upon energy being a real substance existing in fluid and solid forms. According to his theory energy is the only substance to exist and is the aether that exists throughout the whole of infinite space. This energy is a fluid substance that is extremely compressible. His theory claims the universe is in a steady state and not expanding as the redshift of starlight is mostly due to the loss of energy by photons as they move through space and due to random motions between galaxies. He also claims his theory does not need theoretical concepts such as dark matter, dark energy, neutron stars or black holes. Mash has written a book describing his theory Wot, no bang?: A New Scientific Theory of Creation (2008) and claimed on a forum in 2008 he was in the process of submitting his theory to a peer-reviewed journal. He has updated his website in 2013 but there is no sign of any scientific publications regarding his theory.

The Cosmic Time Hypothesis (CTH), See here and here, is based on the General Theory of Relativity and makes use of its degrees of freedom for an extension of the time term. According to the CTH, the universal time scale expands to the same law as the expanding universe. By means of this "cosmic space-time", accordingly physical reality can be described more comprehensively and plausibly compared to the present standard model of cosmology. This hypothesis can be described as a non-mainstream version of the Big Bang model. (transferred from 'talk' page)

The Pan Theory was proposed in the early 1960s by Forrest Noble as being a "simpler" cosmology and a completely different model of modern physics, claiming that observation and Occam's Razor were its primary development principles. The theory proposes a model of pushing gravity with its own gravity equations, and its own formulas to calculate distances, brightnesses, and time dilation. This model proposes that dark energy and non-baryonic dark matter do not exist, as well as proposing a "simple" beginning to the universe without a Big Bang or Inflation. It is a mechanical “Theory of Everything", proposing to be able to unify all of physics under a single all-encompassing theory. Galactic redshifts are explained by a diminution of matter process rather than by the expansion of space. Space would appear to be expanding but instead matter would be very slowly getting smaller, a type of scale-changing theory. New matter would be steadily created from the matter decrement, maintaining a constant density of matter and a steady-state condition conserving matter and energy. The universe accordingly would be far older but not infinite in size or age. It is also an aether theory, a single fundamental particle theory and a single matter-innate physical-force theory. A related scientific peer-reviewed paper has been published and other(s) are claimed to be in the process of publishing, as of 2014. The last website edition to this model was also dated 2014.(transferred from 'talk' page)

This recently published work is based on the Ritz-type VSL Theory has connections to the work of Wilhelm Weber (in 1864) and Walter Ritz (in 1908), who attempted to develop alternative forms of electromagnetism. A suitable modification of Maxwell equations is proposed in the article
here, which enables a source-velocity-dependent variable speed of light (VSL)
that captures typical relativistic effects in optics and high-energy particles and overcomes some of the mathematical modeling challenges for a Ritz-type VSL theory for cosmology. The results show that the proposed (relative-velocity-based) model can be used to derive Hubble's law and is consistent with the time dilation seen in current cosmological observations. Moreover, the work provides potential explanations to current anomalies in cosmological observations such as: (i) the presence of large number of spectroscopic binaries with short time periods even though nearby visual binaries are not seen with such short time periods; (ii) the apparent lack of time dilation in quasar observations even though time dilation has been observed in supernovae (SNe) light curves; (iii) the possibility that some quasars might be closer than the distance predicted by their large spectroscopic redshifts; and (iv) the difficulty in identifying supernovae progenitors.

The Dichotomous Cosmology, introduced by Y. Heymann in 2014, is inspired by the tired light theory. It describes a universe where the material world is static and the luminous world is expanding. This cosmology enables the reconciliation of the static universe of Einstein with observations of the expanding Universe. Specifically, the theory is reported to conform with the following observations: the relationship between luminosity distance and redshift of supernovae; the stretching of supernovae light curves by a factor (1+z); and the factor (1+z)4 for the radiation energy density inferred from the Cosmic Microwave Background Radiation [2]. The dichotomous cosmology is corroborated by a cosmological test based on the zCOSMOS observations carried out using the Very Large Telescope at the ESO Paranal Observatory. The source code for the simulation used in the cosmological test is available online here. Furthermore, the Etherington's distance-duality equation is a consequence of the dichotomous cosmology.

The General Theory of Stellar Metamorphosis is a planet/star centered cosmology which states stellar evolution is actually planet formation. This means that out of the millions of galaxies observed, they all contain hundreds of billions of planets, and that we can actually see them as they are bright when they are young. This theory has enormous consequences to the likelihood of life in the universe down to the chemistry of the Earth as it evolved from a much hotter, bigger star very early in its evolution.

Although cosmological theories and hypotheses in general are difficult to disprove, strong evidence against them might be found. Maybe five years or more after the James Webb space telescope and the Atacama long baseline radio-scopes are fully functional, expected to be about 2024, it will be announced that they will have found at the farthest observable distances some old, very large and red appearing elliptical and spiral galaxies, maybe with observably high metallicity in accord with predictions of cosmological models of an older or infinite-age universe. This would be strong evidence that the universe is much older and that the Big Bang model would likely be wrong. On the other hand, if only small young, blue-appearing galaxies with minimal metallicity were instead observed at these farthest distances (with no old appearing large galaxies), then all theories and hypothesis proposing an older or infinite age universe seemingly would also most likely be wrong — which would include nearly all of the alternative cosmologies above. Or scientists will discover a very old star, that according to their calculations is considerably older than the estimated age for the Universe[3].

Another problem with an infinitely old Universe[4], or at the very least one considerably older than ours, comes courtesy of the Fermi paradox. No matter how rare would be for an advanced civilization to appear and be able to expand across galaxies against the Universe's expansion; having a literal eternity before our times a whole lot of them would have appeared and even if any of those civilizations had not come here before or contacted with us, the evidences of their existence would be detectable elsewhere.

↑See HD 140283. Note that stellar evolution calculations, being based on theoretical models, have a very large margin of error and is far more likely said star and others that seem to be older than the Universe formed after the Big Bang, not before.